India today received full backing from Thailand in countering terrorism, with the two countries deciding to conclude an extradition treaty. They also decided to share information about terrorists through an institutional mechanism.After the discussions DPM L.K. Advani had with Thai PM Thaksin Shinawatra and Deputy Premier Wissanu Kreangam it was announced that the two countries had ‘‘expressed full agreement and willingness’’ to conclude an extradition treaty.Indo-Thai mutual cooperation will also cover drug trafficking and counterfeiting of travel documents. Advani, who arrived here last night on a three-day visit to Thailand, to be followed by a visit to Singapore, had a busy day meeting the top leadership.